The present invention relates to a transfer device for use in image forming apparatus which is operative to transfer a toner image formed by electrophotographic image formation to a recording medium such as a recording sheet (hereinafter will be referred to as “recording sheet”) via an endless belt. More particularly, the invention relates to such a transfer device operative to transfer a toner image from an image carrier to the endless belt or a recording sheet on the endless belt by the use of a transfer roller.